scott



L. I.. SCOTT.

SAFETY DEVICE EUR coMBusTIoN SYSTEMS.

APPLICATION FILED MAY 9 1919.

-IIlrItxIVi L. L. SCOTT.

SAFETY DEVICKE FOR COMBUSTION SYSTEMS.

APPLICATION FILED MAY 9. 1919.

1 ,$20,936. Patented Nov. 4, 1919.

2 SHEETS-SHEET 2.

A TTRNEV UNITED STATES PATENT oEEIoE.

LEWIS L. SOOTT, OF ST. LOUIS, MISSOURI, ASSIGNOR TO STANDARD ENGINEERING COMPANY, OF ST. LOUIS, MISSOURI, A. CORPORATION.

SAFETY DEVICE EAOR COMBUSTION SYSTEMS.

To all whom it may concern.'

Be it known that l, LEwIs'L. SCOTT, a citizen of the United States, residing in the city of St. Louis and State of Missouri, have invented new and useful Improvements in Safety Devices for. Combustion Systems, of which the following is a specificution. V

This invention relates'to combustion 'systems in which, preferably, oil is used as the combustible'material, although the invention in itsbroadest 'sense is not limited in application te oil burners, and has for its general object the provision of means for stopping the' operation of the system in the evcnt that ignition should not occur when the oil, gas, or other combustible medium is supplied to the burner, or if combustion,

for :my reason, should cease after once starting, as', forexample, if the tank containing the oil should become empty.

The invention has for its further object the provision of means for rendering operative an ignition device forthe fuel after the pressure thereof reaches a certain point and for rendering inoperative the-ignition device when the fuel pressure reaches another point.

In the present case-the invention is embodied in a combustion system employing oil as the fuel, Aand in the-accompanymg drawings illustrating such embodiment:

Figure 1 is a view partly in elevation and partly in section illustrating, more `or less diagrammatically, one embodiment of thePJ invention; f

l `ig. 2 is a sectional plan view of the' base ortion of a furnace with the inlet pipe or the combustible mixture connected t thereto and showing the means for igniting such mixture; and

Fig. 3 is a view similar to Fig. 1 but illustrating amodiiied construction.

Referring now to the drawings, theuiu-I meral 1 indicates a furnace provided iiiitsv bottom with a combustion chamber 2,150",4

which is connected a pipe 3 leading from a blower 4. Mounted in the 'pipe 3 is a cone- .shaped ignition chamber 5 in the smaller end `of which is located a spray nozzle 6. Mounted on the pipe 3 and extending' through the wall of the ignitionchamber 5- is a. spark-plug 7 Extending'through the pipe 3 and connected to the spray-nozzle 6' is a pipe 8 for supplying oil to the spray:"-

Specification of Letters Patent. .Application led May 9, 1919. Serial No. 295,839.

Patented N ov. 4, 1919.

nozzle. This oil lis supplied to the spray nozzle under pressurethrough the medium of a pump 9 operated from a motor 10.

The motor 10 also rotates the fan of the when the oil passes to the spray nozzle 6 it will be under suliicient .pressure to produce a spray. The oil employed may be kerosene and isderived from a tank 12 which may be wholly or partly buried beneath the basement-floor 13. A pipe 14 provided with a check-valve, 15 affords communication between the tank 12 and the pump 9, and the latter communicates with the pipe 8 through the medium of a short pipe 16.- From this latter pipe, or connection, the pipe 8 extends to the pressure chamber 17 of a fuel pressure gage having aBourdon tu-be 18. The pin 19 ofv this tube actuates the hands of the gage (not shown) and also eii'ects the operation of a cut-olf lever 20 pivotally mounted at 2l and a second cut-ofi' lever 22 pivotally mounted at 23, the functions of which will befpresently described. A needle valve 8 is inserted in the pipe 8 between the pump 9 and chamber 17, which valve may be turned to produce a small opening in order to delay the action .of the gage. That is to say, without this valve the fuel pressiue would register' the full amount on the gage in a second or two, which, as will be understood from the operation of the device later given, would be undesirable. for the spark p'lug 7 is supplied from a dry battery 24 and a spark coil 25. The 1111-' 4the spark plug. A wire 27 leading from the primary winding of the spark coil is connected with a stationary contact 28. A wire 29l connects the lever 22 with a second stationary contact 30. A return wire 31 leads from the cut-out lever 2O to the battery 24. The motor 10 is driven by current derivedpfro'm' the city wires, and this circuit is controlled by a temperature regulator indicated, generally., by the numeral 32 located in. one of the rooms in the house. The wires 33 vand 34e leading to the motor are connected to the city wires by a switch 35. The wire4 33 is connected by means of a branch wire 33 with the cut-out lever 20.

The current from the wire 34 is connected to the binding post of a stationary contact 42 with which a trip lever L3 is held in contact by means of a latch 4t engaging under the end thereof. From the trip lever 43 a wire l5 leads to the motor, thus completing the'circuit. YVhen the temperature in the room selected exceeds a given degree, the regulator 32 breaks the circuit of the motor at46, and stops the operation of the motor and henceof the ent-ire system. A pipe 4:7 communicat ing at any convenient point with the vdischarge from the blower 4 leads to and communicates with the interior of a casing 48 provided with a diaphragm 49, which 1s acted on by the pressure of the blower through the pipe 47, A post 50 extends up-4 ward through the casing 48, one end of said post resting on'the diaphragm 49 and the other As-importing the free end of the contact lever 39. The other end of said'lever is provided f with a contact-point 51, which is adapted to cooperate with a contact point 5; ou the cut-out lever 9.0.' The operation of the embodiment of my invention described above is' as follows1 In the normal position of the parts, with the circuit to the motor broken at .35, the cut-out' lever Q() will be in engagement with the contact 30. but the circuit to the spark plug will be. broken by reason o; .the fact that the pin 19 will rest upon the free end ot the cutout lever 22 and break connection ol' the lever with the contact :28. When the circuit to the motor is closed by moving thc switch 35. the` fan of the. blower l Vand the pump 9 are placed in operation. Thepump 9 forces the oil into the pipe S, but due to the pop-valve 11 in said pipe this oil cannot pass to the spray nozzle until the pres-PJ sure has reached. satvztcn pounds. when the pop-valve will open and the oil be sprayed into the ignition chamber 5. In the meantime the oil has also been forced through the needle valve S and exerted its pressure on the Bourdon tube 1S which latter moves the pin 19 upward releasing-the free end of the leve r if and permitting its opposit' end to move into engagement with the contact 28 and thus close the circuit tothe spark plug 7, whereupon the spray will be ignited.4 The adjustment ot' the parts is such that the lever 2; will not make connection with the contact 2S until the pressure registers on the I *same .before the system can again be placed gage, say, tive. pounds. This will occur justbct'ore. or at the same time as, a pressure of ten pounds is reached at the pop-valve 11. This insures that the oil will be ignitcdby the spark plug as soon as it is sprayed. The

pressure ot' the kerosene may continue t0 increase until a given degree of pressure,

say, twenty pounds, is reached, at which time the adjustment ol' the parts is such that the pin 19 which has continuedto move upward, will engage with the lree end of the cut-out lever 2O and move its opposite end downward to break connection with the contact 30, and thus break the circuit to the spark-plug. When the parts are operating and combustion occurs, there will be created arelatively high pressure in the pipe 47, due to the expansion of gases in the-combustion chamber opposing the discharge of air from the blower. This pressure will be exerted on the diaphragm to raise the lever 39 and thereby lower the contact point 51, so that when thel cut-out lever 20 is moved by the pin 19, as previously described, to break connectionv with the contact 30, the contactpoint 52-will not engage the cpntact 51, the latterV being movedO 'by the action of the diaphragm L9 below the limit of downward movement of said contact/ point 52. In the event, however, that ignition of the sprayed fuel did not occur, or having occurred, that combustion thereafter, should cease, it will be apparent that pressure in the pipe 47 will p not, be created,or will fall, asthe case may be, and that the contact point 51 will remain in its uppermost postion,`or be-returned to such position by fall of pressure in the pipe 3 permitting the diaphragm to fall. In the first case, that is to say, when combustion does knot occur, as soon as the lever 20 is actuated by the pin 19 to break connection with the Contact 30, the Contact 52 will at once engage with the contact 51 and thereby place the magnet 36 into the circuit of the motor 10, whereupon the latch #l1 will be pulled outward and release the trip lever 43 which will at once fall and break connection with the contact 42, thus breaking the .circuit of the motor and stopping the operation 'of the system. In the event that combustion break the circuit to the motor in the man- 'ner just described.

The circuit to the motor having once been broken by the action of the magnet switch,

'the system cannot again be placed in operation until Vthe, magnet switch has been reset; and, of. course, the householder, or operator, is apprised bythe fact of the action of the switch that there is some trouble'v in the system, and must correct the inoperation. For example, suppose the oil supply has become exhausted and the operation of the system discontinued by thc 'action of the magnet switch; should the operator reset the switch and place the 'system in operation, the switch/ would at once be actuated to break the circuit and stop the motor and the parts willl return to the normal, or inoperative, position. Thus the unnecessary use of current from the battery 2i is prevented. Again, assume that a short-circuit occurs in the circuit of the spai'l:--pl1u f, and the operation of the system is discontimied in the manner described. If ille operaba' again places the system in operation a t'ter resetting the magnet-switch,

the latter will be again instantly operated and stop the motor, and the useless .and dangerous supply of oil to the combustion chamber be prevented.

In Fig. 3 I have. illustrated another arrangement for effecting the automatic breaking of the motor circuit should combustion.

not occur or, having occurred, shouldcease. ln this embodm'ient-of the 1nvent1on the safety device is actuated by-the temperature .of the furnace and not from a'pressure regeulator. Totbis end I connect to -thefurnace at any suitable point, say -t-he main draft4 pipe 53, a controlling device, in tl1e`.for1n offf a-mereurv tube 5l, which communicates with the-interior of a diaphragmzfvalve 55,the.

diaphragm 56 of which actuates a post"57l which engages the end o'f-a lever 58p1voted y at 59. In this case onewire '60 of the motor the trip lever 43 to-the motorini-'Theother' circuit leads to the binding post lof thestationary contact l2, and a wire G1 leadsA from wire 62 of the motor circuit-leads fronrlthe switch 35 to the motor anda branch wire 63 leads from-thewire 62 to a coil'i of a solenoid 65. A branch wire 66 also leads-from the wire 61 to said coil. wire 67 leadslfrom the Wire 66 to the coilof a-magnetGS and a wire 69 leads from saidl coiItot'he'cut-outj The numeral 70l indieatesthecore lever 58.

of the solenoid, vin the upper endfof whichy is mounted a post 714 extending upward through the top of the solenoid-:casing and carrying a transverse contactmember 7 2,'the upper end of whichpost 71i is adapted to engage or lbe engage by a contactmember 73 on the upper end of the cut-out lever58.

The numeral 74 indicates astationary conv. tact-plate, which is adapted to be slidablv engaged b v the contact member 72. The

wire 3] from the battery eleads to the contact member 7;. The wireV 27 from'tlie primary of tbe spark plug coil leads to the vcontact plate 7l. Mounted on the lowei` end of the core 70 is a piston rod 75 which projects through the top of a dash-pot 7 6 and carries at its lower end a piston 7 7 snugly engaging the wall ot said dashfpot, which wall is protidw i above and below said piston with small oiiices 78 and 79. The operation of this modified embodiment of the lollows* When the circuit to the motor is closed at the switch 35, if combustion occursthe'expausiou of the mercury. in the tube 5l acts` invention is as to depress the diaphragm 56 and raise the outer end of the cut-out lever 58. When the motor circuit is closed the core 70 of the solenoid will be raised and after a certain time the contact member 72 will engage and slide overandthen off of the contact plate 74e. During the time the-member??J is in engagement with the'contact plate 74 the circuit to the spark plug T will be closed. The movement of. the .core 7 Q lnay be nicely timed bythe dash-pot176' to insure that the member 72 will` not engage with the cont-act plate 74 until the requisite pressure of oil, say, ten pounds, has been created at the pop-valve 11. This timing, of course, is eected by the size of the orices78 and-7 9, which regulates the amount of compression of air and of suction bythe 'piston 77'to resist the upward move- =ment oft 1e core 70. When the circuit to the -`motorjs broken,- a coil'spring 80 surround- 'fing'the-piston :rod -75 insures the quick return ofxthelcorez'Ogthe opening-7 9 being suf- `iciently largeg to permitthe-free escape of ithezair-from beneatlrthe piston. In the upward movement ofthe post lits upper end willinotfengagef'the contact 7 3 on'the lever 58 as'the latteriwillhave been moved beyond fthe limit 4ofalpward 'movement of the post 71 --by the .diaphragm 56. Assuming, however, that-combustion didi not'occur when the system was placed'in operation, the diaphragm 56 "would not be'ldepressed and the contact 7member 731would' remain in the lowermost position. vAs isoon, therefore, as the post 7l was.` raised by ftlie'l'solenoid. its upper end would engage the -contactmember 73 and thereby place the magnet. 68 into the motor circuiti.i The latch 44 would vthereby be withdrawn by themagnet, allowing the trip lever 43 to fall .and break-the circuit to the motor. Various Aother -Ways of utilizing .the principle of-my invention for effecting the auto- -matic cut-out of the Amotor under a condition J of nonrcombustiomfmay be devised; and. the two constructions illustrated will be suicient -tof'show'that the broad idea of my invention' is not dependent upon a particular but that my invention consists broadly in the provision of-automatic'means, whereby, in a.- system Such as described, when the motor :is placed in` operation, any preferred controlling device will 'be actuated, which in turn construction for effecting the desired result will; be placed in position to be acted upon by.v acoperating device, controlled by conditions in the combustion-chamber, the two devices co-actinginthe absence of combustion to break-the motor circuit, or to remain inoperative, s'offaras their prescribed functionV is concerned, so long as combustion continues.

'I'claim'r 1 1 j",

1.`In a combustion system comprising'a combustion chamber, means for feeding fuel thereto and means forl igniting saidfuel,

safety means comprising automatic cut-out mechanism operatively connected with the fuel feed means and directly responsive to and regulated by combustion conditions, said cut-out mechanism operating upon an initial failure of ignition, or upon cessation v tion of non-combustion -and rthereby#effectv tbefcut-.ofl' oftlie fuel supply to fthe; combus.

of combustion after ignition of the fuel, to cut olf the fuel supply to the combustion chamber.4 1'

2., In a, combustion systeml comprising a combustion chamber, means for feeding fuel theretoand means for ignitingfsaid fuel,

6. In a combustion system comprising a combustion chamber, means for feeding fuel thereto, and means for igniting,r said fuel, electrical means for operating the fuel feed means including an electrical circuit, a circuit) breaker included in said circuit, movable contact members also included in said circuit, one of said members being responsive to combustion conditions and the other being automatically movable to operative safety mechanism comprising a device and:-

nieans for automatically bringing tlie'same into action when fuel is fed to thejcombustion chamber, a second device adapted to be automatically brought into action when combustion takes place in the combustion chamber, said devices constituting-.elements position when the system is placed in operation, whereby under a condition of conibustion the said contact members will be maintained out of contact, and under a comlition of non-combusticu the second-named -contact member will engage the first and of a eut-out mechanism`-and being arranged that thetrst named-device 4ivillact on the second named :device `sunderf a condition chamber. l 3. In a combustion syst-emjcomprism s:

l combustion chamber, means for feeding# uel thereto and means for igniting rsaid fuel,

.safety means comprising .copeiating\de Vices adapted to be brought into.action,the one by "the feed of the fuel and the other by theoccurrelace of combustion one of said devices being responsive ,to combustion conditions and operating under a condition of non-combustion t0 coperate with the-other device to cut-olf the fuel supplyv to the conibustion chamber. L

4. In a combustion `system comprising a combustion chamber, means for-feeding fuel thereto and means forigniting said*` fuel,

means including anelectrical --circuit :forI

operating the-fuel feed,l land automaticcutout mechanisms included in .fsaid circuit, comprising a device brought-into action by the fuel feed and a device responsive tol close the circuit to the circuit breaker, and tlierebLbreak 4the circuit tothe fuel feedin" means. I

1- In a combustion system comprising a combustion cliambennieans for feedingvfuel thereto and-means for igniting said fuel, electrical means including lan electrical circuit-fon actuating the :fuel feed means, a cuit breaker included in said circuit, a pair `of `contact members included in said circuit und mutually and automatically"movable in tlie same direction in the operation of the system, the one bythe occurrence of combustion-and the other by the operation .of the system, whereby ,under a condition ofcombustion said contact members will be combustion conditions, saiddevices, -upon -1 occurrence of non-combustion, being adapted to eoperaie to break the .circuit -to .the `fuel feed means .and thereby cut-off the supply of fuel to the combustion chamber.

. 5. In a combustion system comprising a combustion chamber, means for-feeding fuel theneto and'nieans for .igniting said fuel,

means including an electrical circuit. for

operating the fuel feed v-means, and .auto-4 matic cutout meclianismcomprising w device adapted to be brought into action when the circuit is closed to the-fuel means` and a coperating deviceresponsive to com! bustion conditions, said devices being fin-f ,maintained out of contact, and under a condition -of non-combustion,- the latter contact member will engage the first and close the circuit to the circuit breaker and thereby break the circuit to the fuel feeding means.v

8. In a,y combustion system comprising a' combustion chamber, means for feeding fuel thereto and. means'for igniting said fuel, electrical mea-ns foriactuating the fuel feed means including an electrical circuit, a cir- -euit breaker included in said circuit, a pair f the fuel feeding means.

eluded in said circuit and operating under.:r`

a condition of non-combustion `to coperate and eti'ectx .the breaking of the' circuit to the fuel feed means and thereby cut off the supply of fuel to the combustion chamber.

v 9. lIn a. combustion system comprisin a combustion chamber, means for feeding uel thereto and a. spark plug for igniting the fuel, an electric circuit including the spark plug, electrical means includin an electrical circuitfor operating the fuel l(freed means, a circuit breaker in the'latter circuit, a circuit controller commoifto both circuits and normally-closing the former and governed by the pressure of the fuel, a movable contact `member in said latter circuit for cooperation breaker 'and thereby stop the fuel feeding -10. In 'a combustion system comprising aA combustion chamber, means for feeding fuel thereto and a spark-plug for igniting the fuel, an electrical circuit including said spark plug, a pair of circuit-controllers in said circuit, an actuating member common to said circuit-controllers and responsive to the pressure of the fuel, whereby at a given pressure of fuel, one of said controllers will be caused, yby movement of said member, to close the circuit to the spark-plug and at a given higher pressure the other controller .will be caused by the actuating member vto break thc circuit to the spark plug.

` 11. In a combustion system comprising a4 combustion chamber, means for feeding fuel thereto yand a. spark plug for igniting the fuel, an electrical circuit including said spark plug, a. pair of circuit controllers in said circuit, an actuating member common to said circuit controllers and responsive to the pressure of the fuel, said actuating member working between said controllers and being normally in engagement with one of them 'to hold it in open-circuit position, and the other controller being normally in closedcircuit position, whereby at a given pressure of fuel the former controller will be released by the movement of said actuating member to close the circuit to the spark-plug and at a given higher pressure said actuatingV member will engage the other controller and move it to open-circuit position to break the circuit to the spark plug. p

12. In a combustion system comprising a combustion chamber, meaxm for feeding fuel thereto and a spark plug lfor igniting the fuel, a circuit including the spark plug, -cirycuit controlling mechanism comprising a lurality of devices automatically controlled in the operation of the system to place said spark lug in the circuit at a given period after t e system has been placed in o eration and to cut out said spark plug a er a further period of operation, cut-out mechanism for the fuel feed comprising a movable member responsive to combustion conditions, and one of said devices, said movable member being adapted to be placed in an inoperative kposition with respect to said device by the`occurrence of combustion and if combustion` fails to occur to remain in a. position to be engaged by said device to cutout the fuel feed.

In testimony whereof I have hereunto set my'hand." i, y I

LEWIS L. SCOTT.A 

